The invention herein is a padlock with a built-in anti-theft alarm device utilizing the rotation of a pintle bar revolving a cam such that the lobe pushes against and closes an electric switch which initiates the operation of an alarm circuit, while a vibration sensor device triggers the alarm circuit to emit an alarm sound whenever abnormal vibration is detected and thereby achieves the objectives of offering a durable lock with a built-in reverberating anti-theft alarm.
Since motorcycles and bicycles have the advantages of lightweight physical construction and high-speed capability, these vehicles have become the most popular type of transportation tools today. Based on the same reasons, motorcycles and bicycles are easily stolen and owners have resorted to a wide range of anti-theft measures, the most common being the wheel lock, an anti-theft method that consists of placing a padlock at the wheel of the vehicle, or the installation of an electronic anti-theft alarm connected to the electrical system of the vehicle. However, these two anti-theft measures often have the following shortcomings:
1. The installation of a padlock cannot easily anti effectively discourage thieves and, given the advanced techniques utilized by such persons, the padlock is often rendered ineffectual regardless of its precision and durability. With sufficient time and a complete set of tools, a highly skilled thief can pry a padlock open or simply break the padlock, a task which in a majority of cases is not difficult to achieve. PA1 2. While a number of padlocks have anti-theft features, an organized group of thieves can disable the anti-theft capabilities by moving the vehicle to another location and covertly removing the padlock. Therefore, such enhanced padlock devices are useless in such a situation since it is impossible for the owner to be aware of the theft. PA1 3. Electronic anti-theft alarms installed on vehicles are not only expensive in price, but only sound an alarm upon detecting vibration. Safer protection is still ensured by the fastening of a strong padlock. Therefore, the vehicle thief need only quickly access the wiring and cut the connection to the power supply to move the vehicle.
Based on the foregoing discussion, it must be acknowledged that most motorcycles and bicycles are not as costly in value as automobiles and, therefore, the higher price of automobile anti-theft devices makes them unfeasible for protecting motorcycles and bicycles. As a result, the motorcycle and bicycle padlocks or anti-theft alarms sold today each have respective protective functions and shortcomings that have lead to high rates of vehicle theft, making it necessary to improve such anti-theft methods.